If I was going to do a lot of highway commuting, I would go with the 16 front sprocket. Decreasing rpm will also decrease vibration and increase gas milage. If you want to accelerate harder, just drop down a gear.
It could make 6 th gear into more of an overdrive gear and it could reduce your top end speed in 6th gear. (my 750 is set up that way....it will top out at a higher speed in 4th gear than it will in 5th, but it is oh so dead smooth and quiet in 5th)
My 1150 turns 3800 at 65 mph, so I think I'll leave that alone. 
Earl
It could make 6 th gear into more of an overdrive gear and it could reduce your top end speed in 6th gear. (my 750 is set up that way....it will top out at a higher speed in 4th gear than it will in 5th, but it is oh so dead smooth and quiet in 5th)
Earl